Questions tagged [electromagnetic-induction]

Filter by
Sorted by
Tagged with
0
votes
1answer
16 views

How does current/component voltage phase difference calculated in pure circuits remain the same for mixed circuits?

In class, we derived the phase difference values between the component voltage and the circuit current for pure inductive and capacitive circuits. Later, while doing LR, RC, and LC circuits, we used ...
0
votes
1answer
49 views

Is there a circulating $E$ field when a single straight wire cuts a magnetic field?

I am a little confused as to the difference between the Lorentz force and Faraday’s induced emf, specifically in the case of a straight wire moving through a uniform B field. I know the answer is that ...
0
votes
3answers
46 views

Can one explain the attraction of two magnets with Faraday's law?

Supose two ideal magnets, close to each other and both at rest, with a north and a south poles both fixed and well defined. May we admit as well that the total electric charge of both is zero in the ...
2
votes
1answer
45 views

How are people able to procure sounds from electromagnetic waves?

I have found out about this video: https://www.youtube.com/watch?v=lO5ehpdZ5Po, and also this one: https://www.youtube.com/watch?v=Cga3DfaLc7A. The first one is about a device called the Elektrosluch (...
0
votes
1answer
27 views

Uniform electric field formation in motional emf induction

Why is the electric field $E$ across the ends of a conducting rod, when it's moved with a uniform velocity $v$ in a magnetic field $B$, uniform? Wouldn't it vary non-linearly, since there are opposite ...
0
votes
2answers
65 views

Induced current in a closed loop in opposing directions

When a magnetic field is given to the loop as in the figure(sorry for the horrible drawing); I'm told that there will be an anticlockwise current induced in both the 'inner' and 'outer' loops, ...
0
votes
0answers
4 views

Induction of a Polar Molecule in Electrostatics Clarification

Is it correct to state that one of the ways polar molecules, such as water, are polarized, is charging via induction? As far as I know, charging via induction is only for conductors. Is there a ...
-1
votes
0answers
12 views

The relationship of current in a piece of wire and the voltage across it

i want to test the motional emf between two points on a wire, which is moving in a uniform magnetic field. I know that this is primarily due to magnetic induction, but i am not sure whether using a ...
0
votes
1answer
40 views

Equations governing electromagnetic induction

I wish to generalise the equations governing electromagnetic induction. Consider a loop whose size is changing, and is subject to a changing magnetic field. Then, Definitions: $$\phi \equiv\int_{S(t)}\...
0
votes
0answers
24 views

Why do tokamaks need to operate in pulsed mode?

The plasma current is normally induced by a transformer coil in the plasma. A Tokamak therefore does not operate continuously, but in pulsed mode like the transformer. https://www.ipp.mpg.de/1766212/...
0
votes
1answer
31 views

How is a current induced in this translating wire?

I am familiar with the principles of electromagnetic induction, but I am stuck on the scenario below: a long straight wire is translating in a uniform magnetic field. According to my book, this causes ...
1
vote
1answer
87 views

Faraday's law for a 3-dimensional conductor plate moving in a uniform magnetic field

I am struggling to understand this supposedly simple problem I found in a highschool textbook. A metallic plate is moving with constant velocity v in a region in which there is a uniform magnetic ...
0
votes
0answers
14 views

What happens when velocity of a square loop and the constant magnetic field point in the same direction?

In class today we were learning how to calculate the induced current and induced EMF when the square loop was moving across the field, so velocity was perpendicular to the constant b-field. What ...
2
votes
4answers
85 views

Will a changing $E$ field induce a current in a loop similar to a changing $B$ field?

An induced current in a wire loop that is caused by a changing B field is a common EM question. However, I couldn't find examples online where the B field was substituted for a changing E Field. The ...
0
votes
2answers
34 views

Motional EMF and magnetic flux

For a current carrying closed wire, when the flux of magnetic field changes, there is an emf which is induced, given by the formula: $\epsilon= -(d\phi/dt)$ Here, $\phi$ is the magnetic flux and $\...
0
votes
0answers
21 views

Grow Synthetic Crystals at home with Induction Heater [closed]

Using an induction coil with a graphite crucible is it possible to grow synthetic crystals at home with this setup? I know that the setup would have to include some precise control of vertical draw (...
1
vote
0answers
20 views

Can induction go through metal with holes?

I intend to use (Qi) wireless charging for a project of mine. It uses induction coils to transfer power wirelessly. In my project, between the coils there will be a 1.5mm sheet of brass. The first ...
0
votes
1answer
42 views

Explaining how a magnetic field affects currents in a conductor, in the limit of high conductance

Recently, I gave an answer to this question, explaining my intuition on how much electric field impinges into a good conductor under certain conditions, in order to reason about the limit of perfect ...
0
votes
0answers
17 views

What is the importance of magnetuc flux cutting the surface of coil

Iam a bit confused about magnetic flux lines cutting a coil say if we have a rectangular coil abcd like in the dynamo and the sides ab and cd are perpendicular to the magnetic flux when the plane of ...
3
votes
6answers
315 views

Induced electric field inside a perfect conductor

If I have a magnetic field and I place a coil that is a perfect conductor in this field that I'm rotating. This would mean that there is a change in the flux through the area of the coil which would ...
0
votes
1answer
19 views

Back emf when circuit is closed and opened and the conservation of energy

Ok, this might sound like a stupid question but I am legitimately confused. Imagine a circuit connected to a solenoid. When a circuit is closed (by a switch), there will be a quick increase in current,...
1
vote
0answers
17 views

How to find inductance using $\phi=L I$ for distributed current case? [closed]

A current flows via two long coaxial cables. I know that one can find the inductance $L$ by using $\phi=L I$ but in this case where is the loop through which I should find the flux? Is it even ...
0
votes
1answer
20 views

Induced electric field and electric field due to charges obey superposition?

Say a group of charges and a varying magnetic field exists in some region. We'll have two electric fields,due to the charges and due to the magnetic induction. Does the total electric field equal the ...
0
votes
0answers
35 views

Self-inductance, back EMF and energy stored in magnetic fields

First let's talk about self inductance. A current-carrying loop produces a magnetic field which in turn produces a flux through the loop. If this current is increased, the flux changes as the magnetic ...
1
vote
2answers
16 views

Does an induced magnetic field in a conductor change the existing current in the conductor?

So a conductor placed in a changing magnetic field induces a current in the conductor. This current induces a new magnetic field counter-acting the existing magnetic field. This will change the ...
0
votes
0answers
14 views

How do deep-seeking “two-box” metal detectors work?

There is a type of metal detector known as a "two-box" metal detector, which is able to find much deeper objects than a traditional metal detector. The back coil is often referred to as the ...
2
votes
1answer
29 views

How to calculate induced energy?

Suppose we have a fixed copper coil with $n$ turns. It has no iron core. We throw a magnet through it with speed $v$ and we don't need to account for gravity. How do we calculate the induced ...
-1
votes
2answers
49 views

Induced emf with no relative motion

When we change the magnetic flux encompassed by a loop, an induced current is produced. We know that the induced current is often explained with either the motion of loop with respect to the magnetic ...
0
votes
1answer
22 views

Inductor EMF direction

I have some serious troubles with understanding the EMF in inductor. Assume we change the current from value $I_0$ to zero by rotating the tumbler of the source. Then why should we consider the EMF ...
1
vote
0answers
30 views

Inductor in a circuit

Could someone explain me how there have to be accumulation of charges on the terminals of the inductor and the surfaces of the conductors? I have the following argument, please correct me if I'm wrong....
0
votes
0answers
26 views

Do magnetic fields have any effect on quartz?

I am designing an induction heating component and am wondering if anyone could tell me what effect the magnetic field would have on the quartz glass parts, if any. The actual heat inductor would be ...
1
vote
0answers
30 views

How to determine the “polarisation” of the magnetic field caused by magnetic induction?

I'm having trouble wrapping my head around the idea of magnetic induction caused by the current flow in a wire. Considering that the magnetic field created by current flow is circular in its very ...
1
vote
2answers
42 views

How is there self-induction at the moment of closing the circuit?

I have just learned about self-induction and I'm confused about something. There was a problem where there was a battery connected in parallel with a bulb both connected in parallel with a coil, the ...
0
votes
1answer
21 views

Time to magnetize iron

How long does it take for the magnetic domains of a piece of iron to align (and form a magnetic field) from the moment it enters in contact with a magnetic field?
0
votes
0answers
15 views

Incident plane wave on metal rings

in this article an incident electromagnetic plane wave on a periodic sequence of square metal rings is considered. The authors say: When the transverse magnetic field faces the vertical strips, it ...
0
votes
0answers
14 views

Stationary conductor in a time varying magnetic field, emf equation

A question has been asked before, but hasn't got a detailed answer. For a conduction loop in a time varying magnetic field, we get the emf as the rate of change of flux in inside the loop. But, in the ...
3
votes
4answers
81 views

Polarity in a magnetized Möbius strip [closed]

When a flat iron or Alnico washer is magnetized one of the faces develops a north polarity and the other, south. The geometric shape here is simple. However, when a standard Möbius strip (or one of ...
0
votes
1answer
24 views

What equation should I use to calculate inductance of a wire coil?

I've been working on a project recently which requires me to build an inductor, however in my research I found many different equations (with a range of variables used and giving very different ...
0
votes
1answer
73 views

What will be the direction of the induced current in the loop due to the other loop?

Say I have a circular loop in which current is flowing which is being increased as time passes by. And beside it in the same plane there is another circular loop which isn't connected to any circuit. ...
1
vote
3answers
124 views

How does the coil rotate?

I came across this question in one of my tests. But I was unable to understand which way does the coil actually rotate ? Any visualizations would be quite helpful. As per the given question I thought ...
0
votes
3answers
47 views

Why is the curl of magnetic field $0$ outside the conductor and non-zero inside? [duplicate]

I dont understand why the magnetic field does not curl outside the cable, according to this example, since I would expect the magnetic field lines to go back on themselves around the cable like shown ...
1
vote
1answer
27 views

Mutual inductance - induced magnetic flux in the primary

Let there be two coils, L1 (with self inductance L1), and L2, with self inductance L2. The first coil is connected to a sinusoidal supply, and the second one is connected to a resistor load, as shown ...
0
votes
1answer
7 views

What is the significance of the electron's wavelength for Momentum and Energy Resolved Tunneling Spectroscopy (MERTS)?

The technique called momentum and energy resolved tunneling spectroscopy (MERTS) is based on quantum tunnelling, whereby an electron can traverse a barrier which has a thickness of less than 3nm, by ...
0
votes
1answer
27 views

Faraday's law. Why does the induced current flow this way?

We have this stationary loop in a time-varying B-field. The current I (in red) is induced by the changing field B(t). This current in turn induces a B field that opposes the changing field due to ...
0
votes
3answers
51 views

Faraday's law and inductors

We can calculate the voltage across an inductor as $$V=-\frac{d \Phi}{dt}$$ I am not sure why can we write this since an inductor isn't a closed-loop, which is a condition for Faraday's law. I am also ...
1
vote
1answer
25 views

Can you induce motion by changing magnetic field on a body which isn't magnetic?

In this video demonstration of Lenz's law, the narrator starts with a substance which doesn't respond to the magnetic field of a bar magnet yet when he moves the bar magnet in relative motion to the ...
0
votes
1answer
69 views

An attempt to solve Feynman's Disc Paradox

The following paradox is mentioned in the Feynman Lectures on Physics Vol II, Chapter 17, Section 17-4. I have seen various solutions to this paradox across the internet and even on this Stack ...
0
votes
2answers
36 views

Energy density of Induced Electric Field

For electrostatic fields, we write the energy density using $$u = \frac12\epsilon_o E^2$$ is this formula also valid for a non-conservative electric field produced by changing magnetic field? Or, can ...
1
vote
0answers
17 views

Electrostatic Induction Metal vs Insulator

If we have a small dielectric sphere and a point charge, they will experience an attractive force due to electrostatic induction. Likewise, if we have a small metallic sphere and a point charge, they ...
0
votes
1answer
48 views

Faraday's Law (General form) and the Change in flux

For the Introductory E&M class, I am taking this year I was working on some problems involving the general Faraday's Law $$\oint{E.dS}=-\frac{d\phi_B}{dt}$$ I was confused regarding, How we ...

1
2 3 4 5
25